Ladder clamp



April 1951 c. M. MCKENZIE 2,550,365

LADDER CLAMP Filed Aug. 22, 1947 A) N v e:

TEJI -Il I in im l-II|-mlI v INVENTOR. C/arerrce/f M AeIr /e.

ATTORNEY Patented Apr. 24, 1951 UNITED STATES PATENT OFFICE LADDER CLAMP Clarence M. McKenzie, Canfield, Ohio Application August 22, 1947, Serial No. 770,104

.2 Claims. (01. 24-263) This invention relates to a device for holding ladders in position on various carrier means such as found on trucks and the like.

The principal object of the invention is the provision of a ladder clamp for detachably affixing ladders to carrier means on trucks and the like. 7 v v A further object of the invention'is the provision of a ladder clamp of an adjustable type which is quick acting in use and which may be operated to securely grip a ladder regardless of the thickness thereof.-

A stillfurther object of the invention is the provision ofaladder clamp having a stationary jaw and an adjustable jaw, the adjustable jaw incorporating a secondary adjustable jaw therein and secondary adjustment-means for moving and simultaneously locking the same with respect to the stationary jaw.

The ladder clamp disclosed herein isso formed as. to facilitate the carrying of ladders and the like on various carrier means applied to trucks and'the like; for example, transversely positioned overhead racks on truck bodies and/or cabs. The device may also be afiixed to the sides of a truck or to the vehicle or supporting surface and a ladder placed directly therein and held securely thereby.

With the foregoing and other objects in View which will appear as the description proceeds,

ing drawing, wherein:

Figure '1 is a side elevation of the ladder clamp with parts broken away and parts in cross section.

Figure 2 is a top plan view taken on line 2-2 of Figure 1. V Figure 3 is an end elevation taken on line 3-3 of Figure 2.

By referring to the drawings and Figure 1 in particular it will be seen'tha't a ladder clamp has been disclosed which comprises a body member I3 having an elongated bar positioned therethrough and the bar ll! having a jaw H formed thereon and at right angles thereto. A plurality of notches or openings 12 are formed in the elongated bar [0, the body member l3 acting as a guide holding the movable bar ID in predetermined relation thereto and slidable longitudinally thereof.

The body member l3 comprises a housing having a movable jaw I l reciprocally positioned therein and adapted to be moved outwardly therefrom as indicated by the arrow in Figure 1 of the drawings. A bar-like extension I5 is aflixed to the body member l3 and extends outwardly therefrom and toward the stationary jaw ll on the bar l0. A mounting bracket i6 is affixed to the opposite side of the body member 13 and has a plurality of openings ll therein so that the ladder clamp may be mounted on a supporting object such as a truck. The housing comprising the body member l3 has a bottom member 18 which engages the bottom of the elongated bar I0 and a transverse guide pin ii! is positioned between the side walls of the housing comprising the body member [3 and engages the top of the elongated bar Ill.

A transversely positioned pivot pin 20 is positioned between the side walls of the housing comprising the body member l3 and pivotally mounts a latch, 2| which is normally urged by a spring 22 into engagement with one of the openings I2 heretofore referred to, to hold the bar ll] against movement. A portion 23 of the latch 2| extends out of the body member l3 and serves as a handle andit'will be seen that by moving it upwardly toward the elongated bar In the portion of the latch 2i engaging one of the openings M! will be disengaged therefrom so as to permit the body member iii to be moved longitudinally on the elongated bar it.

, It will thus be seen that when a portion of a ladder (such as one of the side rails thereof) and a cross member of a ladder carrier on a truck are positioned in the space between the movable law l4 and the stationary jaw l l, the body member [3 may be moved along the elongated bar ll! to bring the movable jaw I4 into proximity to the ladder or carrier.

In order that the movable jaw [4 may then be forcefully engaged with the ladder or carrier, means is provided in the body member l3 for moving and simultaneously locking the secondary jaw l4. Such means comprises a handle'24, a portion of which is threaded as at 25 so that the handle 24 may threadably engage a block 26 which in turn is pivoted by means of pivot pins 27 to the side Walls of the housing. The innermost end of the handle 25 has a bracket 28 pivotally mounted thereon and carrying a transverse pivot 29. The transverse pivot 29 and the movable jaw M are connected to one another by indicated by the arrow in Figure 1.

means of a pair of links 30. The links 30 engage the movable jaw I I by means of a pivot pin 3I positioned transversely thereof.

It will be observed that at such time as the body member I3 is moved into proximity to the object to be clamped in the area between the movable jaw I4 and the stationary jaw II, the movable jaw I4 may be moved to clamp upon the object by moving the handle 24 downwardly as Such action causes the pivoting of the handle 24 on the pivot pins 2'! and the forward movement of the innermost end thereof which is transmitted by the links 30 to the movable jaw I4. It will be obvious to those skilled in the art that when the pivots 3'- 21, 29 and 3| line up on a center line and the pivot 29 moves past the same a locking action is obtained which firmly locks the movable jaw I4 on the object in the clamp. It will also be seen that the clamping and locking position of the movable jaw Il may be varied substantially by rotating the handle 24 and thereby changing the spacing of the pivots 27 and 29 as the same move closer to one another when the handle 24 is rotated in one direction and further away from one another when the handle 24 is moved in the opposite direction. This action contributes greatly to the successful operation of the ladder clamp as it enables an approximate positioning of the body members I3 to be had by sliding it along the elongated bar I and an accurate clamping and locking action to be had by reason of the adjustability of the movable jaw I4. If, for example, the object in the clamp is relatively wide and when the movable jaw I3 is moved into proximity therewith, only a narrow space exists between the same and the object to be clamped, the handle 24 may be rotated to move the same inwardly of the block 26 and increase the distance between the pivots 21 and 29 and thereby move the movable jaw I4 out into engagement with the object to be clamped. When the handle 24 is then depressed, the pivots 27, 29 and 3! line up on a center line, and when the pivot 29 moves over the center line a locking action is obtained.

An additional locking action is possible with the device by reason of the provision of a threaded butterfly nut 32 which is threadably engaged on the threaded area of the handle 24 and is provided with a cone-shaped portion 33 which will engage the space between the spaced side walls of the housing comprising the body member I3 so that it may be held in immovable position by reason of positioning beneath a pair of oppositely disposed short studs 34. Thus, When a device is to be clamped in the clamp, the butterfly nut 32 may be turned into engagement in the housing of the body member I3 and below the studs 34 and thereby lock the whole device in clamped position. It will be understood that this is a secondary locking action and operates independently of the locking action obtained when the pivot 29 is moved past the center of a line drawn through the pivots 2'! and SI.

In Figure 2 of the drawings the preferred relative size and positioning of the bracket I6 is illustrated and it will be observed that when the clamp is mounted on the side of a truck or simi lar vehicle the bracket I6 provides a satisfactory mount for the body member I3 making it, in effect, stationary. In operating the device so mounted, the elongated bar I0 is moved to bring the jaw II into proximity to the device to be clamped and the clamping action obtained, as heretofore described.

In Figure 3 of the drawings an end view is disclosed which illustrates the latch 2I more advantageously than the showing in Figures 1 and 2. It will also be observed that the block 26 and its pivotal mounting on the pivot pins 21 are clearly shown as is the butterfly nut 32.

It will thus be seen that a simple and efilcient ladder clamp has been disclosed which incorporates a novel adjusting and clamping action making possible the securing of devices, such as ladders clamped therein, and providing two separate and distinct locking actions.

Having thus described my invention, what I claim is: p

1. A ladder clamp comprising a body member, a bracket on said body member enabling the same to be attached to a support, a longitudinal passageway through said body member and an elongated bar slidably disposed in said passageway, one end of said bar being upturned to form a jaw, a movable jaw positioned in said body member, a latch in said body member normally engaging the said elongated bar, a longitudinally threaded lever and means threadably receiving said lever and pivotally positioned in said body member, and a link' and swivel connecting said lever with said secondary law, the said lever movable longitudinally with respect to the said pivotal positioning means thereof by reason of said threaded engagement therewith.

'2: The ladder clamp defined in claim 1 and further characterized by the inclusionrof a projecting guide on said body member spaced with respect to said elongated bar by the said movable jaw and partially enclosing the area between the said movable jaw and the stationary jaw.

CLARENCE M. MCKENZIE.

REFERENCES CITED The following references are of record in'the file of this patent: 1

UNITED STATES PATENTS Switzerland of 1909 

